A larger version of the bottle brush that is able to reach to the bottom of standard carboys used in the homebrewing process. These brushes will often have a 90 degree bend in the bristled portion allow the shoulders of the carboys to be scrubbed.

WARNING: A carboy brush should never be used on a Better Bottle as it will scratch the plastic. This creates places bacterial infections can hide from cleaning and sanitizing solutions thereby making it unsuitable for fermentation and/or conditioning.